The entire towns of Healdsburg and Windsor are set to evacuate ahead of strong winds that may lead to erratic fire behavior.
The Sonoma County Sheriff's Office expects to be the biggest evacuation in the county in over 25 years with Sheriff Mark Essick saying its the largest evacuation order he's experienced in his 26-year career.
"This fire is very dangerous," Essick said at a press conference Saturday.
Weather forecasts indicate that strong winds are set to impact much of the region over the weekend. Some gusts are projected to reach 85 mph and there's a possibility of it being a record wind event, the National Weather Service warned,
"The winds are expected anywhere between 8 p.m. and midnight and from all reports they're expected to be extremely strong," said Brian Vitorelo with the California Department of Forestry and Fire Protection.
The Mayor of Windsor encouraged residents to get out quickly.
"This is a life-threatening situation and a danger to our entire town," Foppoli told ABC News.
Pacific Gas & Electric (PG&E) confirmed it would initiate a mass power shut-off of nearly 940,000 customers on Saturday, with the total impacted rising from 2.5 to 2.8 million.
PG&E will shut off power in six phases, beginning at 2:00 p.m. on Saturday, Oct. 26, and ending at 10:00 a.m. on Sunday, Oct. 27. The warning was announced as firefighters battled flames in Northern and Southern California.
The Kincade Fire has burned 25,455 acres and was 10 percent contained, according to Cal Fire. More than 23,500 structures are at risk of being damaged.
A blaze on Thursday destroyed at least six homes in the Santa Clarita area near Los Angeles and led to evacuation orders for up to 50,000 residents, although many were allowed back home after Santa Ana winds began to ease. As of Saturday afternoon the blaze was 25 percent contained.
Authorities said Friday human remains have been found in the burned area. The Los Angeles County Sheriff's Department said the death is under investigation but it's too soon to know whether the death was connected to the fire in Santa Clarita.
To the north, firefighters raced to make progress against a blaze near Geyserville in Sonoma County before ferocious "diablo winds" returned. The fire had burned 49 buildings, including 21 homes, and swept through nearly 40 square miles of the wine-growing region. It was 10% contained by Saturday morning.
Several thousand people living in small communities in neighboring Lake County were warned to be ready to evacuate if an order is given. The area was the scene of a 2015 wildfire that killed four people and burned nearly 2,000 homes and other buildings.
High winds this weekend could ground water-dropping aircraft, disperse fire retardant and drive hot embers far ahead of the flames to set new blazes, Cal Fire Division Chief Jonathan Cox warned.
"You can't fight a fire that's spotting ahead of itself a quarter of a mile, half a mile, in some cases a mile ahead of itself," he said.
No cause has been determined for any of the current fires, but PG&E said a 230,000-volt transmission line near Geyserville had malfunctioned minutes before that fire erupted Wednesday night.
The utility acknowledged that the discovery of the tower malfunction had prompted a change in its strategy.
"We have revisited and adjusted some of our standards and protocols in determining when we will de-energize high-voltage transmission lines," Andrew Vesey, CEO of Pacific Gas & Electric Co., said at a briefing Friday.
The weekend forecasts detail what could be the strongest winds of the year coupled with bone-dry humidity.
"These places we all love have effectively become tinderboxes," Vesey said. "Any spark, from any source, can lead to catastrophic results. We do not want to become one of those sources."
The possible link between the wine country fire and a PG&E transmission line contained grim parallels to a catastrophic fire last year that tore through the town of Paradise, killing 85 people and destroying thousands of homes in the deadliest U.S. fire in a century.
State officials concluded that fire was sparked by a PG&E transmission line.
Asherah Davidown, 17, of Magalia and her family lost their house, two dogs and a car in the Paradise fire. She said her family was preparing for another power outage by filling the gas tank of their car and buying non-perishable foods and batteries for their flashlights.
The outages reminded her of her family's vulnerable position as they struggle to get back on their feet.
"My house doesn't have a generator so that means another weekend of sitting in the dark with no Wi-Fi, no food in the fridge and shopping in increments since we don't know how long the power may be out," Davidown said.
The continuing round of power outages made her feel somewhat vulnerable as her family tries to get back on its feet, she said.
"For the most part, a lot of people feel really helpless. Their livelihoods are at the fingertips of a corporation," she said. "There's still a lot of hurt and emotional recovery. Having our basic needs repeatedly taken away is really unfortunate."
The Associated Press contributed to the report